about two lattice in a same simulation Sio2 and W

Dear exports,
I want to do a friction for a SiO2 and W,

but when I do this project

It has a wrong message for Incorrect args for pair coefficients and
Last command:pair_coeff * * W_zhou.eam.alloy W

I have a idea for that problem is that I dont define the W atom ,
just that in Sio2 Si is atom 1 and O is atom 2,
but I dont know how I can define for the W atom
or I think is wrong
please help me!!

-----------------------------------this is in file
#mp-558200

units metal
newton on
atom_style charge
dimension 3
boundary p p p

lattice custom 7.136 origin 0.25 0.25 0.25 &
a1 1 0.00000000 .00000000 &
a2 0.00000000 0.97001 .00000000 &
a3 .00000000 .00000000 0.97001 &
basis 0.0513 0.7951 0.5481 &
basis 0.0513 0.2049 0.4519 &
basis 0.4487 0.0481 0.2951 &
basis 0.4487 0.9519 0.7049 &
basis 0.5513 0.2951 0.9519 &
basis 0.5513 0.7049 0.0481 &
basis 0.9487 0.4519 0.7951 &
basis 0.9487 0.5481 0.2049 &
basis 0.0512 0.5 0 &
basis 0.0808 0.3169 0.6585 &
basis 0.0808 0.6831 0.3415 &
basis 0.25 0.158 0.342 &
basis 0.25 0.842 0.658 &
basis 0.4192 0.1585 0.8169 &
basis 0.4192 0.8415 0.1831 &
basis 0.4488 0.5 0 &
basis 0.5512 0 0.5 &
basis 0.5808 0.8168 0.8415 &
basis 0.5808 0.1831 0.1585 &
basis 0.75 0.342 0.842 &
basis 0.75 0.658 0.158 &
basis 0.9192 0.3415 0.3169 &
basis 0.9192 0.6585 0.6831 &
basis 0.9488 0 0.5

region box block 0 50 0 22 -3 3
region above-lo block -1 51 -1 7 -3 3 side out
region below-hi block -1 51 15 23 -3 3 side out
region lo-asperity sphere 32 7 0 8
region hi-asperity sphere 18 15 0 8
region lo-half-sphere intersect 2 lo-asperity above-lo
region hi-half-sphere intersect 2 hi-asperity below-hi

create_box 2 box
create_atoms 1 region lo-half-sphere &
basis 1 1 &
basis 2 1 &
basis 3 1 &
basis 4 1 &
basis 5 1 &
basis 6 1 &
basis 7 1 &
basis 8 1 &
basis 9 2 &
basis 10 2 &
basis 11 2 &
basis 12 2 &
basis 13 2 &
basis 14 2 &
basis 15 2 &
basis 16 2 &
basis 17 2 &
basis 18 2 &
basis 19 2 &
basis 20 2 &
basis 21 2 &
basis 22 2 &
basis 23 2 &
basis 24 2

mass 1 28.09
mass 2 16.0

pair_style tersoff

pair_coeff * * SiO.tersoff Si O

lattice bcc 3.168

create_atoms 2 region hi-half-sphere

pair_style eam/alloy
pair_coeff * * W_zhou.eam.alloy W

min_style cg
minimize 1.0e-12 1.0e-12 1000 1000

intial velocities

compute 1 all pe/atom
thermo 10
thermo_style custom step temp pe etotal dt time
dump 1 all custom 100 W.xyz id type x y z

velocity all create 300 666 mom yes rot yes dist gaussian
fix 1 all nvt temp 300 300 0.05
timestep 0.001
run 3000

there are multiple issues at hand. the error related to the pair_coeff statement can be understood from reading the documentation.

the main problem is that you create your simulation cell with support for only 2 atom types. there should be 3.

setting up a simulation of the kind you are aiming to do requires much more thinking and understanding than you may currently expect.
please note that LAMMPS can have only one active pair style, so your second pair_style command will wipe out the first.
so you would either need a pair style and parameter file that can describe all three atom types at the same time or you would need to use pair style hybrid. that, however, would require you to find additional parameters and use a third pair style, since you have potentials and parameters for each subsystem, but nothing that can describe the interaction between those two. this kind of pair style would - by nature - have to be a pairwise additive potential.

since your goal is to particularly study the interaction between those two subsystems, your first priority should be to find a parameterization/model that is well suited for that. right now you only have something for each subsystem interacting with itself. so it looks like you need to do more literature research.

Axel.